The present invention refers to a coffee machine for brewing coffee powder pre-packed in a cartridge, comprising perforator members for creating openings in the cartridge bottom.
In order to brew coffee powder pre-packed in a cartridge, up to now, mostly semi-automatic coffee machines are used in which the cartridge has to be inserted into a sieve holder with its cap facing downwards, whereby the sieve holder, thereafter, has to be manually fixed to the coffee machine. The coffee machine comprises a brewing pin member provided with radial outlet openings for the brewing water, located in the region of the portion pack holder fixing. The brewing pin member penetrates the bottom of the cartridge when the sieve holder is fixed to the coffee machine. The sieve holder itself is provided, at its bottom, with a plurality of projections. These projections penetrate the cap of the cartridge and perforate it, as soon as brewing water is fed to the sieve holder, whereby the cartridge is pressed against these projections under the influence of the hydraulic overpressure. At the consecutive brewing operation, the brewing water is fed into the cartridge by the brewing pin member, thus flowing through the coffee powder contained therein and escaping from the interior of the cartridge through the perforation in the cap. The freshly brewed coffee beverage can escape through outlets located at the lower side of the sieve holder.
In recent times, fully-automatic coffee machines are available in which a cartridge containing the pre-packed coffee powder is taken out of a magazine containing a plurality of cartridges and displaced to a brewing chamber of the coffee machine. At the bottom of this brewing chamber, perforator members are located which provide the bottom of the cartridge with slots upon closing the brewing chamber. Through these slots, brewing water can flow into the interior of the cartridge. For closing the brewing chamber, such a machine comprises a movable closure member provided with a plurality of projections located at its lower surface facing the brewing chamber. Once the brewing chamber is closed by means of this closure member, the brewing water is lead under pressure into the brewing chamber in the afore mentioned manner.
Thus a hydraulic overpressure is created in the interior of the brewing chamber containing the cartridge such that the cartridge is pressed against the lower surface of the closure member provided with the afore mentioned projections with the result that these projections penetrate and perforate the cover of the cartridge.
Usually, the brewing chamber of such fully automatic coffee machines is part of a user removable module that can be taken out easily, without any tools, by the operator for the reason of cleaning. Thereby, it should be ensured that the operator cannot be injured by the afore mentioned perforator members, mostly in the form of sharp knives located at the bottom of the brewing chamber, for example, if he puts a finger into the brewing chamber.
Thus, it is an object of the invention to provide a coffee machine for brewing coffee powder pre-packed in a cartridge in which such danger of injury is avoided or at least greatly reduced.
To meet this and other objects, the invention provides a coffee machine for brewing coffee powder pre-packed in a cartridge which comprises a brewing chamber adapted to contain the cartridge with perforator members protruding into the brewing chamber adapted to create at least one opening in the cartridge bottom of the cartridge. A protection member is movable relative to the perforators between a rest position and an operating position. The protection means is adapted, once being in its rest position, to bar access to the perforators.
By providing a protection member which is movable relative to the perforators between a rest position and an operating position that, if it is in its rest position, bars access to the perforators, the risk of injury of the operator of the machine is avoided to the farthest extent. Preferably, the protection member is moved from its rest position to its operating position by the afore mentioned closure member during closing the brewing chamber, whereby the cartridge bottom is provided with the slots under the effect of the perforator members when the protection member is in its operating position.